Such an electroacoustic conversion chain gives the possibility of converting an electric signal to be broadcast into an acoustic signal.
Conventionally, the electroacoustic conversion chain comprises a loudspeaker. The latter comprises an axially biased toroidal magnet inserted in a magnetic field. This magnetic circuit delimits a ring-shaped air gap where a magnetic field prevails.
The loudspeaker also comprises a conducting material coil wound and secured around a tube extended with a membrane capable of generating an acoustic wave.
The coil is intended to receive a current depending on the signal to be broadcast and partly extends in the air gap in which it is axially mobile.
The coil has an axial length such that, during the operation of the loudspeaker, all or part of the coil is found in the air gap.
During the operation of the electroacoustic conversion chain, the whole of the magnet is powered. The turns of the coil present in the air gap are subject to Laplace forces which will cause them to move along the axis of the tube. The displacement of these turns causes displacement of the membrane via the tube, causing generation of sound.
This embodiment has an electroacoustic yield because of the losses by the Joule effect in the coil.